Problem in reading Character

Hi All,

I am facing a strange problem in reading a character from stdin. I have wrote the following code:

Code:

#include<stdio.h>
#include<stdlib.h>

void add( int, int);
void sub( int, int);
void mul( int, int);
void swap( int, int);
void reverse( int, int);
int rev(int);

int main()
{
    int num1,num2,ch;
    char c='y' ;
     
     while( c=='y' || c=='Y' )
    {
     
    printf("\n Enter The Two Numbers");
    scanf("%d %d",&num1,&num2);
         printf("\n  Select the operation to perform from the given Menu " );
         printf("\n \t 1. Addition "); 
     	 printf("\n \t 2. Subtraction ");
     	 printf("\n \t 3. Multiplication");
         printf("\n \t 4. Swap the values ");
         printf("\n \t 5. Print both the numbers in reverse order");
         printf("\n \t 6. Exit");
         printf("\n \t Enter Your Choice ");
         scanf("%d",&ch);
         switch(ch)
         {

             case 1:
             add(num1,num2);
             break;  

             case 2:
             sub(num1,num2);
             break;               

             case 3:
             mul(num1,num2);
             break;

             case 4:
             swap(num1,num2);
             break; 

             case 5:
             reverse(num1,num2);
             break; 
            
             case 6:
             exit(0);
             break; 
        
        }

         printf(" Do You Want to continue Y/N "); //Segmentation Fault after this point
         fflush(stdin); 
  
         c=getchar();
  
         scanf("%c",&c); 
     
    }
   
}

I am getting the segmentation fault after printing the Line " Do You Want to continue Y/N" ..

I can't understand why it is giving the same.......

Can Anybody help me in this..........

Thanks
Bargi

Originally Posted by Bargi

I am getting the segmentation fault after printing the Line " Do You Want to continue Y/N" ..

The compiler is allowed to do anything it wants with "fflush(stdin)", including trigger a segfault. The question must then be asked: what do you want this "fflush(stdin)" to do, and then we can look at how to accomplish that.

> printf(" Do You Want to continue Y/N "); //Segmentation Fault after this point
> fflush(stdin);
fflush isn't defined for input streams. It might work, but it's not guaranteed. You could flush the input stream like this:

Code:

         while (getchar() != '\n');
         printf(" Do You Want to continue Y/N ");
         c = getchar();

Thanks for reply.......

Actually I have used fflush(stdin) to flush out everything in input stream ...since some time we face problem when we try to read string after pressing "enter " and it read "Enter" as string (MAY BE I AM WRONG PLEASE CORRECT ME). That's why I have used fflush(stdin).......

Thanks
Bargi

Originally Posted by Bargi

Thanks for reply.......

Actually I have used fflush(stdin) to flush out everything in input stream ...since some time we face problem when we try to read string after pressing "enter " and it read "Enter" as string (MAY BE I AM WRONG PLEASE CORRECT ME). That's why I have used fflush(stdin).......

Thanks
Bargi

scanf will read enter (or \n, etc.) when reading a character, not a string. (IOW: if you're willing to deal with the overhead, read in a string using %NUMBERGOESHEREs.) The fact that you want to use fflush(stdin) does not change the fact that fflush(stdin) does not, in fact, actually exist.

Hehehe
http://cpwiki.sourceforge.net/Undefined_behaviour